Re: [Stox] Stephen Farrell's IESG feedback on draft-ietf-stox-core

Stephen Farrell <> Mon, 10 February 2014 22:20 UTC

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Date: Mon, 10 Feb 2014 22:20:34 +0000
From: Stephen Farrell <>
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To: Peter Saint-Andre <>, The IESG <>
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Subject: Re: [Stox] Stephen Farrell's IESG feedback on draft-ietf-stox-core
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Hi Peter,

On 02/10/2014 06:24 PM, Peter Saint-Andre wrote:
> ( + STOX WG since one of the issues might deserve broader discussion )
> Hi Stephen, thanks for your review:
> You wrote in part:
>    - I wondered why you didn't just say that (D)TLS SHOULD
>    be used/supported between gateways. Given that all the
>    relevant bits of code are likely to support that, wouldn't
>    it be a good thing?
> Yes, that seems eminently reasonable.

Just to be clear - the above is the only DISCUSS point.

>    - Has anyone thought about confusability in the name
>    mappings? I expected to see a bit of text in the
>    security considerations but didn't see it.
> Confusion is always possible. :-) Were you thinking about confusable
> characters from Unicode, or something else?

Right. Maybe its all there already and I just didn't see
if in the mapping stuff, or maybe not. I'm not sure.

>    - It seems a shame to not be able to gateway when the To is
>    a sips URI at all but I understand that some loss of
>    security is inevitable for cases like this. Is there any
>    work planned for an update that would allow gatewaying for
>    such cases, e.g. if the 1st XMPP server is the one to which
>    the user is connected and the user is connected using
>    XMPP/TLS?
> Hmm. I cannot say that I am aware of planning for updates to provide
> more secure gatewaying, although folks active in the STOX WG might be
> thinking along those lines.
> Depending on the deployment architecture, I think there are cases where
> it is *possible* to TLS-protect all the hops. For instance, if
> has a direct server-to-server connection to
> (no intermediate hops) and both organizations agree to
> force the use of TLS for client connections (e.g., via SLA), then I
> suppose that could honor 'sips' URIs when sending
> traffic to However, such an arrangement is rare enough
> right now that I don't know if it is worth mentioning.

Fair enough. I can see that detecting that you (probably) have
all (D)TLS hops might be tricky and error prone.


> Peter